The present invention relates to pump type dispensers for liquids such as liquid soap, and particularly to that type of dispenser having a valved pump which lifts the liquid from a suspended vessel through a dip tube.
Pump mechanisms for lifting and dispensing such liquids have taken many forms, but are ordinarily constructed to operate in upright position, in which a piston plunger is pressed downward. The valves in such pump mechanisms may operate in part by gravity. This arrangement, well suited for hand-held dispensers, is inconvenient for use in factories and institutions where dispensers of hand cleaning substances are mounted on walls; for such use it is easier to press a pump plunger horizontally. Dispensers having plungers so aligned usually drain the liquid to be dispensed from a vessel positioned above the level of the plunger. Such non-pumping dispensers do not require two valves in the line of flow. However, they are more subject to leakage and their liquid-containing vessels are not readily changed.